We plan to continue our long-term investigations of mechanisms of non-specific resistance to infection and intoxication by studying the role of complement and complement components in disease, the nature of gene products of the major histocompatibility region, the differentiation of cell surface markers in patients with immunodeficiency diseases and deficiencies in resistance to infection, suppressor cells in immunodeficiency diseases and in development of hematopoietic cells, LMIF production. We will also study the immunodeficiencies in experimental leprosy, the contributions of the major histocompatibility region in experimental leprosy and the possibility of development of immunotherapy of leprosy.